A 3D light field display technology is considered as one of most promising technologies in the field of 3D display. In the 3D light field display technology, a real and remarkable glasses-free 3D display effect can be achieved and an image can be performed in real-time.
A structure of a current display device adopting a light field display technology of an ordinary-display is shown in FIG. 1, and a basic principle of the current display device is that: the device is based on a light screen with small holes and an ordinary display, an image displayed in the display may be coded by a computer to obtain light field display units with an m×n resolution, then a direction and intensity of each light emitted from the light field display units may be controlled by open holes of the light screen, that is, an array formed by the light field display units obtained by modulation in a coding manner is displayed on a display screen, the array is demodulated by the small holes with specific optical parameters in a space domain, and formed light information is mutually superimposed to obtain spatial light field information of a target object. Human eyes are able to receive the spatial light field information to fit a natural form of the target object, so that an observer is able to observe an object image in a real 3D effect without glasses.
A schematic diagram illustrating formation of a spatial light field by light field display units of a display device through small holes in a related art is shown in FIG. 2. A resolution determined by a coding manner determines the number of viewpoints provided by the spatial light field. When a sub-image array formed by the light field display units includes m rows and n columns and each light field display unit corresponds to an open hole, the number of the viewpoints of the formed light field is m×n, that is, m viewpoints form horizontal light field information, and n viewpoints form vertical light field information. Therefore, such a technology may form parallaxes in both horizontal and vertical directions to achieve a spatial full-parallax 3D effect. The 3D effect and feeling of depth in the horizontal and vertical directions are positively correlated to the number of respective viewpoints.
However, the abovementioned current ordinary-display-based 3D light field display technology has the following shortcomings. (1) A very high requirement is made on the resolution of the display, or it is difficult to achieve the 3D effect, the current light screen has a very limited light control capability, and a resolution and pixel pitch of a current mainstream display are insufficient to provide a sufficient pixel number and fineness for imaging. For the two factors, the light field display units formed by adaptive coding by virtue of the current light field display technology are low in resolution, the formed image includes small numbers of viewpoints in the horizontal direction and the vertical direction, and it is difficult to achieve an obvious 3D effect. Particularly when the current technology is applied to a Light-Emitting Diode (LED) display with very large pixel sizes and pitches, a formed image may make an observer obviously feel pixel particles, which makes the shortcoming more obvious and causes more serious influence on a watching experience. (2) The loss of the light information luminance is high, and imaging luminance is low. For controlling the directions of the lights of the light field display units as accurately as possible, it is necessary to reduce structure sizes of the small holes of the light screen to block most of the lights, which causes a very low overall light transmittance of the light screen and a very dark final 3D image. Once external ambient light gets slightly strong, the watching experience may be seriously influenced.
For the abovementioned problems, there is yet no effective solution at present.